Vue.component('box', {
  template: `
    <div style="position: absolute; left: 0; right: 0; top: 0; background: rgba(0, 0, 0, 0.8)">
      <slot></slot>
      <div>
        <button @click="$emit('cancel')">cancel</button>
        <button @click="$emit('ok')">ok</button>
      </div>
    </div>
  `
})